Index: src/natools-smaz.adb
==================================================================
--- src/natools-smaz.adb
+++ src/natools-smaz.adb
@@ -1,7 +1,7 @@
 ------------------------------------------------------------------------------
--- Copyright (c) 2016, Natacha Porté                                        --
+-- Copyright (c) 2016-2017, Natacha Porté                                   --
 --                                                                          --
 -- Permission to use, copy, modify, and distribute this software for any    --
 -- purpose with or without fee is hereby granted, provided that the above   --
 -- copyright notice and this permission notice appear in all copies.        --
 --                                                                          --
@@ -111,14 +111,14 @@
             Remaining := 0;
          end if;
       end if;
 
       declare
-         Full_Blocks : constant Ada.Streams.Stream_Element_Count
-           := Remaining / Verbatim1_Max_Size;
+         Block_Count : constant Ada.Streams.Stream_Element_Count
+           := (Remaining + Verbatim1_Max_Size - 1) / Verbatim1_Max_Size;
       begin
-         Overhead := Overhead + Full_Blocks;
+         Overhead := Overhead + Block_Count;
       end;
 
       return Overhead + Ada.Streams.Stream_Element_Count (Original_Size);
    end Verbatim_Size;